The present invention relates to a microphone device, a microphone structure, and electronics using them.
More specifically, the present invention relates to a microphone unit and a microphone structure with reduced wind whistling sound and wind noise. The invention relates particularly to an application built in AV/IT equipment such as a video camera and a cell phone.
In electronics such as a camera, a video camera, and a cell phone collecting sound by a microphone device incorporated in an equipment body, noise (wind noise) derived from wind generated near a microphone, human breath, and so on is collected.
Thus, various techniques for suppressing collection of wind noise have been disclosed.
For example, JP 2010-157964 A discloses a technique of applying digital signal processing to an audio signal collected by a microphone device to reduce wind noise from input voice.
Further, JP 2005-354581 A discloses a technique of mounting a microphone and a microphone cover through an elastic member to suppress sound generated in electronics such as a video camera and vibration and noise transmitted through a housing of the electronics.
Other background art is JP 2001-193330 A.
More specifically, a conventional windshield for a microphone is called a windscreen or the like, and many of the windshields have a structure filled with a porous material such as urethane or are in the form of foaming a vinyl or plastic material. Those windshields are provided around a microphone to prevent wind whistling sound. In those windshields, there have been sometimes found ones which intend to exhibit waterproof property only during an interim period by applying processing, such as water-resistant coating and waterproof spray, onto a surface of a constituent material.
Recently, AV/IT equipment has been rapidly developed, equipment used outdoors like a video camera and equipment that collects sound near a human face like a cellular phone are in widespread use, and there are a lot of AV/IT equipment having a miniaturized microphone unit built-in. Since the AV/IT equipment collects wind generated near a microphone and noise (wind noise) derived from human breath or the like, a countermeasure thereof is required; however, when the above-described porous material or foaming material is used, the microphone unit itself becomes large in size, and thus it is not realistic. Thus, noise is eliminated (attenuation/lack of the relevant sound area) by applying digital signal processing to a collected audio signal.